The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 29, 1998
Filed:
Mar. 20, 1997
H Spence Jackson, Austin, TX (US);
Michael A Margules, Dripping Springs, TX (US);
Sigmatel, Inc., Austin, TX (US);
Abstract
A method and apparatus for converting a digital signal into an analog signal with minimal self generated noise is achieved by a digital to analog converter that includes a current source, a switch circuit, and a gating circuit. The current source provides a current, which is representative of digital data, to the switch circuit. The switch circuit, based on control signals provided by the gating circuit, routes the current to an analog node and/or a reference potential node. The control signals cause the switch circuit to route the current to both nodes when a clock pulse signal is in a first state regardless of the state of the data, to route the current to the analog node when the clock pulse signal is in a second state and digital data is in a second state, and to route the current to the reference potential node when the clock pulse signal is in the second state and the digital data is in a first state. In this manner, an analog representation of the digital data is present at the analog node.